Manufacture of sized papers



Patented Oct. 19, 1937 UNITED STATES MANUFACTURE OF SIZED PAPERS OscarF. Neitzke, Belmont, Mass., assignor to Bennett Incorporated, Cambridge,Mass., a corporation of Massachusetts No Drawing.

Application February 24, 1936, Serial No. 65,435

12 Claims. (01. 92-21) This invention relates to the manufacture ofsized papers. It deals more especially with the manufacture of sizedpapers involving the use of aqueous sizing compositions containingstably suspended or dispersed therein a mixture of hydrocarbon wax androsin and the combination of such dispersed material with papermakingstock preparatory to sheeting of the stock on a papermaking machine.

The use of aqueous emulsions or dispersions of wax and wax-rosinmixtures as paper-sizing compositions is now in vogue in manypapermaking mills. These emulsions or dispersions are generallystabilized by soap or other precipitable l6 protective colloid so thatafter the emulsions have been incorporated into the papermaking stock,as in the beater engine, the wax or wax-rosin particles may be fixed orprecipitated on the stock by the addition of alum or other salt capableof reacting with the precipitable protective colloid and thus "breakingthe emulsions. One papersizing composition widely used at the presenttime consists of a wax-rosin emulsion at least 'part of whose rosincontent is in the form of rosin soap. The rosin soap thus servesinitially as the emulsion-stabilizer and is then precipitated along withthe wax and free rosin on the fibers of the papermaking stock intowhich" the emulsion is incorporated at a suitable stage of stockpreparation, generally in the beater engine.

In accordance with the present invention, I prepare paper-sizingcompositions in the form of aqueous dispersions of hydrocarbon wax-rosinmixtures which, rather than being stabilized by soaps or otherprecipitable protective colloid, are stabilized by inert ornon-precipitable compounds, such as neutral salts of sulphonic acids,preferably sodium or other alkali metal saltsof such acids, orwater-soluble gums of the nature of gum 4 arable. Because of theinertness or non-precipitability of the dispersion-stabilizer present inthe aqueous dispersions of the present invention, it might be reasonedthat they would be ill-adapted for sizing papermaking stock on accountof their inherent stability and the absence therefrom of any addedsubstance that might be precipitated or flocculated so as to entrainand/or fix the sizing solids, that is, the dispersed wax-rosin mixtureon papermaking stock. I have discovered,

however, that through control of particle size in the dispersion andcontrol of the proportion of wax in the dispersed wax-rosin mixture, itis possible to attach or fix substantially all of the dispersedparticles on papermaking stock by the action of a small amount of alumor equivalent mordant salt. In other words, despite the inertness of thedispersion toward alum or similar salt, as attested by the fact that noprecipitation of the dispersion takes place upon' the addition theretoof alum or other salt or electro- 6 lyte in the absence of papermakingstock or pulp, it is possible to discharge or attach its dispersedsizing solids practically completely on papermaking stock or pulp, as inthebeater engine, by the addition of alum or equivalent mordant salt 10thereto. I have termed alum as a mordant by' reason of the fact that itfunctions to attach or discharge the dispersed wax-rosin particles onthe papermaking stock or fibers without noticeable precipitating orclotting action on the particles; 15 and it is my theory that the alumplays a role similar to that of a mordant salt in the dyeing of fibrousmaterial. The mordanting eifect of alum may be readily demonstrated byaddingthe aqueous wax-rosin dispersions hereof to paper- 20 making stockboth in the absence and in the presence of alum and then centrifugingthe mixture to form a compact, partially dewatered layer of stock nextto the centrifuge wall and a separate layer of aqueous medium inwardlythereof. 25 When centrifugation is performed in the absence of alum,it'is found that the separated aqueous medium is of a sizing solidscontent per unit of volume asgreat as that of the original dispersion,whereas, on the other hand, when centrifugation 30 is performedin thepresence of a small amount of alum, it is found that the separatedaqueous medium is substantially clear or devoid'of sizing solids,indicating that the sizing solids have attached themselves to the fibersof the paper- 35 making stock.

I shall now describe a typical and preferred sizing composition for thepurposes of the present invention and how it'may be produced. A

melting kettle is charged with '70 parts by weight 40 of rosin, forinstance, the grade known as G gum rosin and sold to the papermakingindustry for making rosin size, and with 30 parts by weight ofhydrocarbon wax, for instance, so-called scale wax having a meltingpoint of about 124 to 45 126 F. The mixture is melted and heated to a.temperature of about 220 to 250 F., whereupon it is dispersed in partsby weight of a 1% solution of a neutral salt of sulphonic acid, forexample, the salt of this character sold under 50 the trade-mark Daxad",under conditions to produce a finished dispersion at about 180 to F. Thedispersion may to advantage be produced by commingling the meltedmixtureand. the aqueous solution in a high-speed mixer, 65

for instance, a mixing or dispersing machine such as is described inUnited States Patent No. 1,792,067. It is unnecessary to cool thematerials as they are being commingled or the finished dispersion; and,as already indicated, the dispersion as it is'flnished may be at atemperature well above the melting point of either the wax or rosin ofthe dispersed wax-rosin mixture but safely below the boiling point of-water, say, about 180 to 190 F. Upon cooling to room temperature, thedispersion, which has a wax-rosin solids content of about 40%, assumesthe consistencyand appearance of heavy cream. Such a dispersion may bediluted with water to any desired solids content substantially withoutseparation of its dispersed solids, that is, without "breaking.

The dispersion produced as hereinbefore described may be used withexcellent results in the beater-sizing of papermaking stock. Thus, itmay be added in thick, creamy condition or diluted with water to. thepapermaking .stock and its dispersed wax-rosin particles may be fixed onthe fibers with a small amount of alum, which may be added therewith orindependently thereof. The papermaking stock may be made to take upvarious percentages of wax-rosin mixture, for instance, up to 8% ormore, based on the dry weight of fiber, the particular percentage fixedon the stock depending upon the water-repellency or sizing value desiredin the finished paper product. In the case of a substantially neutralpapermaking stock, the use of alum in amount to impart to the stock a pHof about 5 or less ensures the desired retention of the sizing solidsby'thestock. However, irrespective of the pH of the stock andeven whenthe stock contains various electrolytes, it is possible by the use ofabout 1% alum, based on the dry weight of fiber, to cause the stock toretain the sizing solids satisfactorily. Indeed, by using such.comparatively small amount of alum, I am able to discharge the sizingsolids from the'dispersion on papermaking stock even when the stock isdistinctly on the alkaline side and when the stock contains calcium andother salts such as are apt to occur therein and/or in the slushingwater mixed therewith. As already indicated, the dispersed sizing solidsare not precipitated on thestock in the sense that the stabilizerassociated therewithand initially maintaining them in suspension ischemically destroyed or precipitated. They merely. stick to the fibersevidently by reason of their physical attraction, probably electrical,caused by the alum or equivalent mordant .salt, such as aluminumchloride, sodium aluminate, ferric sulphate, or the like. Thepaper-sizing composition hereof is hence practically foolproof, for,whereas the usual aqueous wax dispersion stabilized by soap or otherprecipitable protectlvecolloid is subject to premature precipitation inpapermaking stocks containing salts or-other electrolytes tending toprecipitate the protective colloids and thereby to induce prematureprecipitation and attendant aggregation of the 'wax particles, no suchpremature precipitation and :attendant aggregation of the sizing solidsor particles of the composition'hereof can or.

does take place, in consequence of which papers sized with thecomposition hereof are free from spottiness or irregular and defectivesizing arising from aggregates or unduly large particles of the sizingsolids.

I have conducted extensive research to determine those factorsunderlying and contributing to the results secured hereby. I haveestablished that proper particle size in the dispersions or sizingcompositions hereof is vital to their successful use and. that it isnecessary to produce dispersions wherein the wax-rosin mixture has aparticle size averaging upwards of 5 microns in order to realizefixation of the particles to the papermaking stock by alum or equivalentmordant salt. Unlike the present invention, it. has heretofore been theobjective to produce dispersions of the finest dispersed particle sizeattainable; and it is hence notsurprising that wax sizes or dispersionsas heretofore made have had an average particle size but a very smallfraction of 5 microns. I have found, however, that the dispersionshereof having an average. particle size of 5 microns give perfectlyuniform sizing of paper and that satisfactory sizing results. are alsohad when such dispersions have an average particle size ranging fromabout 5 to 50 microns.

When the average particle size of such dispe'rsions is less than 5microns,-satisfactory retentivity of the sizing solids by thepapermaking stock is not had no matter how much alum or equivalentmordant salt isused in an attempt tofix such solids on the fibers; andwhen theav'erage particle size of such dispersions is greater than about50microns, they do 'not yield'pspers of the desired quality as regardsuniform siflng and appearance.

-While the particular mixing or dispersing machine in which the aqueousdispersions or compositions hereof are'produced and the con ditions ofoperating such machine determine in some measure the particle size ofthe dispersions and should hence be adapted for the production ofdispersions of the particle size herein desired. yet I have foundthatwax and rosinproportionality in the wax-rosin mixture mostimportantly influences the particle size in the disper sions hereofproduced from such mixture. Thus, I have ascertained that if thewax-rosin mix-' ture contains more than 50% wax, it is extremelydifficult to control the particle size in the resulting dispersionthereof on account of the low vis cosity of the melted mixture even whenits temperature after mixing with the aqueous dispersing medium is onlymoderately above its melting point. In such case, despite thefact thatdispersion 'of the mixture is e'flected at the lowest aqueous dispersingmedium,the water' practically boils. Insuch latter case, the averageparticle" size of the dispersed wax-rosin mixture is apt to be too largefor the purposes herein and the dispersed particles tend to settle outon standing;

By dispersing wax-rosin mixtures containing .20

to 50% of wax it is possible readily to keep the average particle sizein the dispersions within the range'of 5 to'50 microns and to reproducesuch dispersions repeatedly invarious mixing or dispersing machines. 80,too, the resulting dispersions are stable or non-separating probablybecause the dispersed'pa-rticles have a specific gravity closelyapproximating that of water. this connection, it is to be noted that thewax having a specific gravity less than 'water buoys up the rosin whosespecific gravityis greater than water, as will be appreciated from thepronounced settling of free rosin that takes place in the,

ordinary free rosin-containing sizes used in the papermaking industry.It is possibly because the floating tendency of the waxsubstantiallyneuin refractive index of the particles, indicating" that the particleshave melted, takes place at a temperature coinciding'almost exactly withthe melting point of the wax-rosin mixture preparatory to itsdispersion. This observation is, of course, also in line with what'Ihave said about the mutual effect of the wax and rosin upon each otherin conducing to dispersed particles of a specific gravity approximatingunity.

There are important advantages inhering in the sizing compositions usedaccordant with the present invention for the production of sized papers,including a saving in alum, the possibility of sizing the papermakingstock in the presence of hard water and at any pH value, the possibilityof adding the size to hot heaters, and the improved color of the sizedpaper products. As to the saving in alum, it might be noted that in thecase of ordinary wax sizes stabilized by rosin soap or otherprecipitable protective colloid,

alum must be used in suificient quantity to ensure the precipitation ofsuch colloid. In all cases of using the sizing composition of thepresent invention, on the other hand, not more than 1% of alum, based onthe weight of the papermaking stock. is necessary to cause the desiredfixation of sizing solids on the fibers. With regard to pH value in thestock or the presence of electrolytes therein, it might be observed thatordinary wax sizes are susceptible to premature breaking in stock oneither side of neutrality and in the presence of hard water, whereas thesizing composition of the present invention is not adversely affected bysuch stock conditions. As to stock temperature, experience has shownthat unless the wax component of the usual soap-stabilized waxdispersions of the prior art is of relatively high melting point, suchdispersions cannot be used when the papermaking stock is hot, as islikely to be the case immediately after a beating operation, sinceelevated temperature tends to break the dispersion prematurely and tocause coalescence or aggregation of the dispersed particles. No suchdifliculty is encountered with the wax-rosin dispersions hereof evenwhen they are made with comparatively inexpensive, low melting pointwaxes, such as scale wax, since they are, unsusceptible to prematureprecipitation or breaking and attendant particle-aggregation under heatsuch as is likely to be encountered in beaten papermaking stock. Thebetter or whiter color of papers sized with the compositions hereof is areflection of the absence of rosin soap from such compositions.-Experience has shown that the higher the free rosin content of a rosinsize or a rosin-wax size, the better or brighter colored is the sizedpaper. The wax-rosin sizing compositions of the prior art generallycontain rosin soapv as the stabilizer; and it is evidently.- the rosinsoap content of such compositions that detract from the whiteness ofpaper sized therewith. It is hence understandable why thesizingcompositions of the present invention, which are devoid of rosin soap,may be used to advantage in sizing white papermaking stocks with minimumdetraction from the whiteness and brightness of the resulting sizedpaper. In addition, the sizing compositions hereof possess all of theattributes of the usual wax-rosin sizes, including capability of.imparting high. water-repellency or sizing value to the papers in whichthey appear. Because the sizing compositions can be applied accordantwith the present invention to papermaking stdck without theprecipitation of aluminum resinate or other compound andwith the use ofonly a very small amount of alum or other mordant salt practicallyentirely removed along with the white water during the papermakingoperation, the size particles fiux better on the hot drum-drlers of thepapermaking machine; so that, despltethe fact that the particle size ofsuch compositions may be much greater than that of prior art sizingcompositions, the. larger particles are fiuxedf'or fused more perfectlyduring the drying oft he paper; In other words, the sizing particles ofwax rosin mixture are substantially unadulterated, that is, aresubstantially free from precipitated rosin soap or other compound thatmodifies or raises their melting point or otherwise interferes withtheir fiuxing on the fibers. In any event. the water-repellent or sizedvalue of papers sized as herein described. compares very favorably withthe water-repellent value of the prior art papers containing the solids.a

It is to be understood thatthe principles of the present invention maybe embodied in a wide variety of practices and products. For instance,the wax component of the sizing composition hereof may .be any one of alarge number of hydrocarbon waxes, including the so-called amorphouswaxes and parafiin wax. I have mentioned scale wax in the examplehereinbei'ore given besame amount of wax-rosin sizing,

cause of its low cost compared with such higherv papermaking stock it ispossible to use salts or electrolytes other than alum, for instance,aluminum chloride, fen'ic chloride, ferric sulphate, 'orthelike.However, alum being colorless, inex pensive, and highly effective isgenerally preferable as the fixing agent for the sizing solids. It isprobably the case that the fixation of the dispersed sizing solids onthe papermaking stock occurs by reason of electrical or electrostatic attraction of such solids to the fibers. I have observed that theparticles of the dispersions hereof are negativelycharged;'and itwould'appear that the alum or equivalent mordant salt serving'to fixsuch particles imparts to the fibers a positive electrical charge thatattracts the dispersed negatively charged particles and fixes them onthe fibers. The positive charge imparted to the'flbers is evidently averyweak one insuflicient to overence therein of dispersed solids: ofsufilclently byany display or significant display of Brownian withwaxerosin mixtures even when mixed there- I with under the elevatedtemperatures hereinbecome the intensive Brownian movement of very fineparticles but of sufiicient potencyto attract particles of the averagesize present in the compositions hereofand possessed of a-specific'gravity so, near, to unity thatythey are sensitive to deposition uponthe-fibers evenas a resultv of very weak electrical pull or attractionby the It is apposite to the present invention to observe that Brownianmovement in aqueous wax rosindispersionspractically stops or iscomparatively when the dispersedparticles are of v a size greater than 5microns, asis the case herein.

Inotherwords, the aqueous dispersions orisizings compositions hereof arelacking or practically lacking in Brownian movement, whereas waxrosindispersions or sizing compositions which were. heretofore made with aview toward developing extremely fine-particle size,=say,, about 1micron, display violent Brownian movement. My

"hypothesis -is, as already suggested, that the retention by papermakingstock of the sizing solids of the, dispersions hereof without the needofchemical precipitating action is linked up with the absenceorsubstantial absence of Brownian movement in such dispersions. that-is,the pressmallraverage particle size, e. g. 5 to,50 microns,

to. be maintained stable in suspension and to be uniformlydistributable. through papermaking stock-and the resulting paper but,nevertheless. of average particle size greater than'that attendedmovement. e

Another noteworthy quality of the aqueous wax-rosin dispersions .01OOmPOSItIODS 118511 for the purposes hereof is that their rosin contentis substantially wholly unsaponified. The substantially unsaponifiedstate of the rosin of such dispersions is attributable to the usetherein 01' a stabilizer that is incapable of saponifying the rosin aswell as being-inert toward electrolytes. The substantially neutral'saltsof ,sulphonic acid answer admirably, asalready indicated, therequirements of a stabilizer herein, for solutions of such salts do notreact measurablyor significantly fore describedv as being necessary forproducing theaqueous dispersions or sizing compositions,

hereof; and these salts are, moreover, inert toward the electrolytesaptto be present in papermaking stocksfor those electrolytes, such" asalumlnumsulphate, aluminum chloride, sodium alu- 'minate, ferricchloride, ferric sulphate, or the, like, preferably added for thepurpose of fixing dispersedi sizing solids, for instance, the dispersedsizing solids ,of the sizing. compositions hereof, on papermakingst ock.It is hence to be understood that. incharacterizing the stabilizers usedherein as being vinertor substantially inert toward electrolytes, suchcharacterization is not meant in anabsolute sense to indicate that thereare no electrolytes capable oi reacting upon such stabilizers but, moreespecially in a sense applicable to the papermaking art to indicate thatsuch stabilizers are inert to the electrolytes usually occurring inpapermaking stock, or electrolytes, like alum, added tothe papermakingstock tofix thesizing solids thereon.

7 It is to be understood thatethe sizing composition hereof may beemployed in sizing all sorts of fibrous materials or paperrnakingstocks, for

instance, rag pulps, .wood pulps, asbestos fiber. wool fiber. ormixtures of such fibers. to be formed 2,090,129v a a 7 into all classesof papers, includingthin or lightv weight papers,-such aswriting','printing, 'maga zinc, and book papers, or thickpap m or "M 1boards,,such as are used f'or' sheathing and insulating purposes or formaking water-repellent containers -or cartons'for foodstuffs and manyother substances, Papermakingistoclsiled as herein described may :alsobe used in making va-' rious molded articles, 80611115! milkbottles-pie; plates, andother molded arti'clesgenerally classifiedaspaper products. I

- While not limited thereto, neutralsodium or 'otheralka'li metal saltsof the sulphonic acids useful herein as stabilizers may be such salts asare prepared from the sludge! separated'as by-products' afteri mineraloils-have been purified or refined by intimate or washing withconcentrated sulphuric acid,

The acid sludges separated from the refined all are rich insuiphonicfacidsi of complex variety, which acids are formed by thereaction of the concentrated sulphuric acid on impui'itiel mciated withthe oil. .By neutralizing the/sulphonic acid sludges iwith caustic (orequiv alent alkali, such salts'as are herein used asstabilizers may beprepared; I sludges may be 1 treated with a concentrated mineral acid toliberate the complexsulphpnic-Icids which, after separation from theresultinglmin eral acid salt and,ln some, instances, the excess mineralacid, may be neutralized with caustic soda or equivalent alkali toproduce the substana tialiy neutral sulphcnic acid salts herein usedasstabilizers In addition to the substantially neutralsulphonic acid saltsavailable on the market under the trade-mark-Daxad, I'may use:

other trade-marked salts of similar nature, for instance, such salts asare being sold under the trade-mark fDipex 0! course, sulphonic acidsalts thatare synthesized or are derived. fromsources other thanmineralgoils may beused as the stabilizers herein, but l have dwelt moreespecially on the useherein of the by-product sul-. phonic acid salts byreason of their availability on the marketat comparatively lowcostand-the excellence of their performance in therirespectl herein desired.a a I I claim:-

l. A process time: sizedpaper involving the use of ahydrocarbonwax-rosin mixture as the sizing material, which comprises.

dispersing such wax-rosimmixture in conditionas particles of asizegreater exhibiting Brownian movement in. aqueous medium containingdissolved therein as the dis persion-stabilizer substantially onlysoluble. dis-1 persion-stabilizer inerttoward and non-precipitable bysuch electrolytes, as aluminum sulphate aluminum chloride, "sodiumaluminate, ferric; chloride, and ferricsulphate, incorporating theresulting dispersion into fibrous pulp in the presenceof an electrolytecapableof causing andfin amount s'ufiici'ent'to cause the. pulp fibersto at-5 tract and retain the dispersed particles, and, forming theresulting pulp, to which the dispersed particles have been attachedsubstantially only by said electrolyte, into a paper product.

2. A process oim'aking a sized paper involving the use of a, hydrocarbonwax-rosin mixture as the sizing material, which comprises dispersingsuch wax-rosin mixture in molten condition as particles of a sizegreater than those,

exhibiting Brownian .movementiin' an aqueous solution'containing'dissolved therein as the dispersion-stabilizer substantiallyonly a .substan- I the names or the neutralized tially neutral salt vofsulphonic acid capable of stabilizing the dispersed particles but inerttoward and non-precipitable by such electrolytes, as, aluminum sulphate,aluminum chloride, 'so-' dium aluminate, ferric chloride, and ferricsulphate, incorporatinglthe' resulting dispersion into fibrous pulp inthe presence of an'el'ectrolyte capable of causing and in amountsufllcient to cause the pulp fibers to attract'and retain .the dispersedparticles, and forming the resulting pulp, to which the dispersedparticles'have'been attached substantially only 'byisaidelectrolyte,

into a paper product.

3. A process of making a sized paper product involving the use of ahydrocarbon wax-rosin mixture as the sizing material, which comprisesdispersing such wax-rosin mixture in molten con-. dition as particlesofa' size greater. than those exhibiting Brownian movement in an aqueousmedium containing dissolved therein as the sta bilizer for the dispersedparticles substantially only a substantially neutral salt inert towardand non-precipitable by such electrolytes 'as' alumi num'sulphate,aluminum chloride, sodium aluminate, ferric chloride, and ferricsulphate and incapable oi saponifying the rosin, incorporating theresulting dispersion in the substantial absence of rosin soap intofibrous'pulp. in the presence of an electrolyte capable of causing and iin amount sufiicient to cause the pulp fibers to attract and retain the.dispersed 'particles,and forming the resulting pulp, to which thedispersed particles have been attached'substantially only by saidelectrolyte, into a paper product.

14. A process of making 'a sized paper product involving the use ofahydrocarbonwax-rosin mixture as the sizing material, which comprises.tract and retain the dispersed particles, and

forming the resulting pulp, to which the dispersed particles have beenattached substantially only by said electrolyte, into a paper product.

5. A process of makinga'sized paper product involving the use of ahydrocarbon wax-rosin mixture as the sizing material, which comprisesdispersing such wax-rosin mixture in molten condition in an aqueoussolutioncontaining dissolved therein as the dispersion-stabilizersubstantially only a substantially neutral salt of sulphonic acidcapable of stabilizing the dispersed particles but inert toward andnon-pre-' cipitable by such electrolytes as aluminum sulphate, aluminumchloride, sodium aluminate, ferric chloride, and ferric sulphate, whilemaintaining the average particle size of the stabilized dispersionwithin a range of about five to fifty microns, incorporating theresulting dispersion into fibrous pulp in the presence of .anelectrolyte capable of causing and in amount suilicient to cause thepulp fibers to attract and retain the dispersed particles, and formingthe resulting pulp, to which the dispersed particles have been attachedsubstantially only by said electrolyte, intoa paperproduct." i

ture as the sizing material, which comprises dis: persing such wax-rosinmixture in moltencondition in-an aqueous medium containing dissolvedtherein as the stabilizer forthedi'spersion' par-- ticles substantiallyonlya substantially neutral salt inert toward and non-precipitablejbysuch electrolytes as aluminum sulphate, aluminum chloride, sodiumaluminate, v ferric chloride, and ferric sulphate and-incapable ofsaponifying'the rosin while maintaining the average particle of thestabilized dispersion Withinarange of about five to fifty microns,incorporatingthe resulting dispersion into fibrous pulp in'the sub-'stantial absence of rosin soap but in the pres'- ence of an electrolytecapable of causing and in amountsufiicient to cause the pulp fibers toattract and retain the dispersed'particles; and forming the resultingpulp, to which'the dispersed particles have been attached'substantiallyonly by said electrolyte, into'a paper product. I 7. A process of makingasized paperproduct involving the use of a hydrocarbon wax-rosin mixtureas the sizing material, which comprises dispersing such wax-rosinmixture in molten condition'and at a wax content ;of about -20% to 50%as particles of a size greaterthan tliosef exhibiting Brownian movementin an aqueous: me-

dium containing dissolved" therein soluble dis-" persion-stabilizerinert toward"and" nonprecipitable by such electrolytes as aluminumsulphate, aluminum chloride, sodium aluminate, ferric chloride, andferric sulphate, incorporating the resulting dispersioninto fibrous pulpin the presence of an electrolyte capable of causing and in amountsuflicient to cause thepulp fibers to attract and retain the dispersedparticles, and

forming the resulting pulp, to which the dispersed particles have beenattached substantially only by said electrolyte, into a paper product.

v8. A process of making a sized paper product involving the use of ahydrocarbon wax-rosin 6. A process of making asizedpaperfproductinvolving the use ofhydrocarbo'n wax-rosin mix mixture as the sizingmateriaLwhich comprises dispersing such wax-rosin mixture in moltencondition and at a wax content of .about 20% to- 50% as particles of asize greater than those exhibiting Brownian movement in an aqueous$01119,

tion containing dissolved therein as the disperfsion-stabilizer-substantially only a substantially I neutral salt ofsulphonic acid capable of stabilizing the dispersed particles but inerttoward and non-precipitable by such electrolytes as aluminum sulphate,.aluminum chloride, sodium aluminate,

ferric chloride, and ferric sulphate incorporating the resultingdisperson into fibrous pulp in the presence of an electrolyte capable ofcausing and infamount sufilcient to cause the said pulp fibers toattract and retain the dispersed particles, and' forming the resultingpulp, to which the dispersed particles have been attached substantiallyI onlyby said electrolyte, into a paper product. 9. A process of makinga sizedpaper product involving the use of a hydrocarbon wax-rosinmixture as the sizing materiahwhich comprises dispersing such wax-rosinmixture in molten condition and'at a wax content of about 20% to 50% p fV V o ingBrownian movement in an aqueous medium i i as particles of asize greater than those exhibitcontaining dissolved therein as thestabilizer for the dispersed particles substantially only a substantialyneutral salt inert toward and non-precipitable by such electrolytes asaluminum sul-"N phate, aluminum vchloride, "1 aluminate, ferricchloride; and ferric sulphate andinoapable offsaponiiying thegrosinincorporating the reu ti z d n i s o li tq iu Pu in e s stantial absenceoivrosin'soap but in thepresence of an electrolyte *capableor causing.and in amount c en i t m e. p er-Sim c a d retainjthejispersedparticles, and forming the resulting pulp, to, which" the dispersedparticles 10 have been attached substantially onlfb'y said electrolyte,into a paper m'od uct. I

I10; Aprocess ormaking' asized pa r'product involving the usefoi ahydrocarbon. wax-rosin migturefas the sizing material, which foomprises'dispersing such wax-rosin mixture in molten} condition and at awax-contentof about 20%to 50% in an aqueousmediumz containingdissolved'there infasthe dispersionstabilizersubstantially only solubledispersion-stabilizer inert toward and non precipitable bysuchelectrolytesjas alumi 'num sulphate,- f aluminum chloride, sodiumaluminate, ferric chloride; and ferric sulphate while maintalning'theaverage particle size-of the Sign bilized dispersionwithin a range ofabout five Lto fifty microns, incorporating the resulting 'disper 1 sioninto flbrous' pulp in the presenceioi' alumin amountsufllcient to causethepulp fibers to' at-E tract and retainithe' dispersed pal-noes; and

pao

forming "the r'esultiht. bulmztojwn ch 15am f-dis persed particles havebeen attached-substantially 7 only byisald alum} int a paper. product.

11.1 A process of m k n a sizedgp'aper product involving the use of ahydrocarbon wax-rosin mixture as the material, which comprisesdispersing such wax-rosin mixture inmolten con;- dition and at a waxcontent of about 20%"to 50% in [an aqueous solution containing dissolvedtherein as the dispersion-stabiliher,

. 12. ,A proce s? by said alum,-intq av'paper product.

only a substantially cles but owe mt nqn predmmbi such electrolytes asage Moe-an o V to cause the pulp fiberite attract rs d: p r c s: andpulp," to which said N 0111135! plenu into i M 'W 'WPM' in l 'ay t e, 0eghv e i x-mun V j fl 'm which 7 i dispersingsuch wax=roain inmolten.dltion a d at e w n nts. .99 1 5% in an ac' ueous}'n'ledimi whe ei t et liz nn -dimmed a mm m neut B l i attached 7 paper product;

substantially only a tart"toward and non-precipitablegbi lytes eel-alumum ulpha a u v tn ln'lt; acid capabl'e ot stabillzihlthedispersedfmsodium m n wne ne chloride; and mu 1 phate and incapable of;e'aponii'yiu:v the the stabilized itmnfle range about nv to fi y i onthe dispersion intoflhm-pulpm. the substantial 1 absence 01 main soapbut in the presence o!v "while maintaining thegurerue pell-tune ina.mount",suflicient the pulp to F attract and retain and form? 1? h r ln pu ktorwh ch, only particles have been attached substantially

